フレッティング疲労の応力拡大係数およびそれによるき裂進展挙動の整理

概要

論文の詳細を見る
The crack propagation behavior in fretting fatigue is divided into two stages, namely : the S_I - and S_<II> - stages. In the S_I - stage, the crack propagation rate da/dN is very high, and decreases to a minimum with crack growth. In the S_<II> - stage, the da/dN increases monotonicly with crack growth. The interpretation of this kind of crack propagation behavior has been rather difficult with a conventional stress intensity factor. In this paper the stress intensity factors under fretting fatigue stress conditions were calculated by BEM. Then the crack proagation behavior was analyzed by these stress intensity factors. The equivalent stress intensity factor for fretting fatigue K_<elf> = √<K_<If>^2+K_<IIf>^2>, where K_<If> is the stress intensity factor for mode I and K_<IIf> is for mode II, was used to represent the da/dN in the S_<II> - stage. The results agreed well with ordinany, or unfretting fatigue results. The revised equivalent stress intensity factor K_<elf>*=K_<elf>・√<(a+a*)/a>, where a is crack length and a* is the crack length at the end of the S_I - stage, was available to represent the da/dN from the S_I - to the S_<II> - stage. These results could be widely applied to data for carbon steel and aluminum alloy.
一般社団法人日本機械学会の論文
1986-11-25